CN114326045B

CN114326045B - Optical imaging system

Info

Publication number: CN114326045B
Application number: CN202210090213.2A
Authority: CN
Inventors: 何旦; 吕赛锋; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2024-05-07
Anticipated expiration: 2042-01-25
Also published as: CN114326045A

Abstract

The present invention provides an optical imaging system comprising: the first lens is provided with positive focal power, the surface of the first lens facing the object side is a convex surface, and the surface of the first lens facing the image side is a concave surface; the second lens is provided with positive focal power, and the surface of the second lens facing the image side is a convex surface; the surface of the third lens facing the object side is a concave surface; a fourth lens having positive optical power, the surface of the fourth lens facing the image side being convex; a fifth lens having negative optical power, a surface of the fifth lens facing the image side being a concave surface; the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface of the optical imaging system and the maximum half field angle HFOV of the optical imaging system satisfy: TTL/tan (HFOV) <2.0mm. The invention solves the problems of miniaturization and high image quality of the optical imaging system in the prior art.

Description

Optical imaging system

Technical Field

The invention relates to the technical field of optical imaging equipment, in particular to an optical imaging system.

Background

Because the camera lens on the mobile terminal is required to be matched with the chip, and the camera lens of the mobile terminal is required to be updated along with the chip upgrading so as to meet the requirement of the modern work rhythm for a faster speed, the field of view is used for providing higher requirements on the portability of the computer, the camera lens is continuously developed towards flattening, and meanwhile, the pixels are required to be lifted so as to meet the requirement of high image quality.

That is, the optical imaging system in the prior art has the problem that miniaturization and high image quality are difficult to be compatible.

Disclosure of Invention

The invention mainly aims to provide an optical imaging system so as to solve the problem that miniaturization and high image quality are difficult to be compatible in the optical imaging system in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided an optical imaging system comprising, in order from an object side of the optical imaging system to an image side of the optical imaging system: the first lens is provided with positive focal power, the surface of the first lens facing the object side is a convex surface, and the surface of the first lens facing the image side is a concave surface; the second lens is provided with positive focal power, and the surface of the second lens facing the image side is a convex surface; the surface of the third lens facing the object side is a concave surface; a fourth lens having positive optical power, the surface of the fourth lens facing the image side being convex; a fifth lens having negative optical power, a surface of the fifth lens facing the image side being a concave surface; the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface of the optical imaging system and the maximum half field angle HFOV of the optical imaging system satisfy: TTL/tan (HFOV) <2.0mm.

Further, the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface satisfies: 1.8mm < TTL <2.4mm.

Further, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens and the effective focal length f4 of the fourth lens satisfy the following conditions: 0.5< f 1/(f2+f4) <1.3.

Further, the effective focal length f5 of the fifth lens and the effective focal length f3 of the third lens satisfy: 0.2< f5/f3<2.9.

Further, the curvature radius R1 of the surface of the first lens facing the object side and the curvature radius R2 of the surface of the first lens facing the image side satisfy: 2.4< R2/R1<3.5.

Further, the effective focal length f of the optical imaging system, the radius of curvature R4 of the surface of the second lens facing the object side, and the radius of curvature R8 of the surface of the fourth lens facing the image side satisfy: -1.3< f/(R4+R8) < -0.7.

Further, the radius of curvature R5 of the surface of the third lens facing the object side and the radius of curvature R6 of the surface of the third lens facing the image side satisfy: 0.1< (R6+R5)/(R6-R5) <0.8.

Further, the curvature radius R10 of the surface of the fifth lens facing the image side and the center thickness CT5 of the fifth lens satisfy: 1.4< R10/CT5<4.0.

Further, the sum Σct of the center thicknesses of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and the sum Σat of the air intervals between the adjacent lenses of the first lens to the fifth lens satisfy: 2.2< ΣCT/ΣAT <3.5.

Further, the combined focal length f23 of the second lens and the third lens and the combined focal length f45 of the fourth lens and the fifth lens satisfy the following conditions: 0< (f23+f45)/(f23-f45) <0.7.

Further, an on-axis distance SAG22 between an intersection point of the surface of the second lens facing the image side and the optical axis of the optical imaging system and an effective radius vertex of the surface of the second lens facing the image side, an on-axis distance SAG31 between an intersection point of the surface of the third lens facing the object side and the optical axis and an effective radius vertex of the surface of the third lens facing the object side, and an on-axis distance SAG42 between an intersection point of the surface of the fourth lens facing the image side and the optical axis and an effective radius vertex of the surface of the fourth lens facing the image side satisfy: 0.6< (SAG22+SAG31)/SAG 42<1.3.

Further, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the edge thickness ET2 of the second lens, and the edge thickness ET3 of the third lens satisfy: 2.8< CT2/ET2+ET3/CT3<3.6.

Further, the edge thickness ET5 of the fifth lens and the edge thickness ET4 of the fourth lens satisfy: 1.0< ET5/ET4<2.8.

According to another aspect of the present invention, there is provided an optical imaging system, comprising, in order from an object side of the optical imaging system to an image side of the optical imaging system: the first lens is provided with positive focal power, the surface of the first lens facing the object side is a convex surface, and the surface of the first lens facing the image side is a concave surface; the second lens is provided with positive focal power, and the surface of the second lens facing the image side is a convex surface; the surface of the third lens facing the object side is a concave surface; a fourth lens having positive optical power, the surface of the fourth lens facing the image side being convex; a fifth lens having negative optical power, a surface of the fifth lens facing the image side being a concave surface; wherein, the sum of center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens and the sum of air intervals SigaAT between adjacent lenses of the first lens and the fifth lens are satisfied: 2.2< ΣCT/ΣAT <3.5.

By applying the technical scheme of the invention, the optical imaging system comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence from the object side of the optical imaging system to the image side of the optical imaging system, wherein the first lens has positive focal power, the surface of the first lens facing the object side is a convex surface, and the surface of the first lens facing the image side is a concave surface; the second lens has positive focal power, and the surface of the second lens facing the image side is a convex surface; the third lens has negative focal power, the surface of the third lens facing the object side is a concave surface, and the surface of the third lens facing the image side is a concave surface; the fourth lens has positive focal power, and the surface of the fourth lens facing the image side is a convex surface; the fifth lens has negative focal power, and the surface of the fifth lens facing the image side is a concave surface; the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface of the optical imaging system and the maximum half field angle HFOV of the optical imaging system satisfy: TTL/tan (HFOV) <2.0mm.

The positive and negative distribution of the focal power of each lens of the optical imaging system is reasonably controlled, so that the low-order aberration of the optical imaging system can be effectively balanced, the sensitivity of the tolerance of the optical imaging system can be reduced, the miniaturization of the optical imaging system is kept, and the imaging quality of the optical imaging system is ensured. The first lens and the second lens are provided with Cheng Zhengguang focal power, light rays can be effectively converged, the third lens and the fifth lens are negative focal power, the system can be ensured to maintain a larger image surface, the aberration of the optical imaging system can be effectively reduced by adopting the positive and negative focal power combination, the imaging quality is improved, meanwhile, the larger deflection of an optical path can be avoided, the positive and negative focal power is distributed in a staggered manner, the abnormal shape of a local lens caused by the excessive concentration of the focal power is avoided, and the processing is difficult. And meanwhile, the TTL/tan (HFOV) is limited in a reasonable range, so that the optical imaging system is compact in structure, and the terminal product is miniaturized and light and thin.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

FIG. 1 is a schematic view showing the structure of an optical imaging system according to an example I of the present invention;

FIGS. 2-3 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system of FIG. 1;

FIG. 4 is a schematic diagram showing the structure of an optical imaging system of example II of the present invention;

Fig. 5 to 6 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system in fig. 4;

FIG. 7 shows a schematic configuration of an optical imaging system of example III of the present invention;

Fig. 8 to 9 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system in fig. 7;

Fig. 10 is a schematic diagram showing the structure of an optical imaging system of example four of the present invention;

FIGS. 11-12 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system of FIG. 10;

fig. 13 is a schematic diagram showing the structure of an optical imaging system of example five of the present invention;

fig. 14 to 15 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system in fig. 13;

fig. 16 is a schematic diagram showing the structure of an optical imaging system of example six of the present invention;

Fig. 17 to 18 show on-axis chromatic aberration curves and distortion curves, respectively, of the optical imaging system in fig. 16;

wherein the above figures include the following reference numerals:

STO and diaphragm; e1, a first lens; s1, a surface of a first lens facing an object side; s2, the surface of the first lens facing the image side; e2, a second lens; s3, the surface of the second lens facing the object side; s4, the surface of the second lens facing the image side; e3, a third lens; s5, the surface of the third lens facing the object side; s6, the surface of the third lens facing the image side; e4, a fourth lens; s7, the surface of the fourth lens facing the object side; s8, the surface of the fourth lens facing the image side; e5, a fifth lens; s9, the surface of the fifth lens facing the object side; s10, the surface of the fifth lens facing the image side; e6, a filter; s11, the surface of the filter sheet facing the object side; s12, the surface of the filter sheet facing the image side; s13, an imaging surface.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

It is noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless otherwise indicated.

In the present invention, unless otherwise indicated, terms of orientation such as "upper, lower, top, bottom" are used generally with respect to the orientation shown in the drawings or with respect to the component itself in the vertical, upright or gravitational direction; also, for ease of understanding and description, "inner and outer" refers to inner and outer relative to the profile of each component itself, but the above-mentioned orientation terms are not intended to limit the present invention.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. Specifically, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, then the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The determination of the surface shape in the paraxial region can be performed by a determination method by a person skilled in the art by positive or negative determination of the concave-convex with R value (R means the radius of curvature of the paraxial region, and generally means the R value on a lens database (lens data) in optical software). In the case of the surface facing the object side, the convex surface is determined when the R value is positive, and the concave surface is determined when the R value is negative; in the case of the surface facing the image side, the concave surface is determined when the R value is positive, and the convex surface is determined when the R value is negative.

The invention provides an optical imaging system in order to solve the problem that miniaturization and high image quality are difficult to be compatible in the optical imaging system in the prior art.

Example 1

As shown in fig. 1 to 18, the optical imaging system includes, in order from an object side to an image side thereof, a first lens having positive optical power, a second lens having a convex surface facing the object side, a third lens having a concave surface facing the image side, a fourth lens, and a fifth lens; the second lens has positive focal power, and the surface of the second lens facing the image side is a convex surface; the third lens has negative focal power, the surface of the third lens facing the object side is a concave surface, and the surface of the third lens facing the image side is a concave surface; the fourth lens has positive focal power, and the surface of the fourth lens facing the image side is a convex surface; the fifth lens has negative focal power, and the surface of the fifth lens facing the image side is a concave surface; the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface of the optical imaging system and the maximum half field angle HFOV of the optical imaging system satisfy: TTL/tan (HFOV) <2.0mm.

Preferably, the on-axis distance TTL between the object side facing surface of the first lens and the imaging surface of the optical imaging system, the maximum half field angle HFOV of the optical imaging system, satisfies: 1.5mm < TTL/tan (HFOV) <1.98mm.

In this embodiment, the on-axis distance TTL from the surface of the first lens facing the object side to the imaging surface satisfies: 1.8mm < TTL <2.4mm. By limiting the TTL within a reasonable range, the total length of the optical imaging system is well limited, the miniaturization of the optical imaging system is facilitated, and meanwhile, the miniaturization of the module is facilitated, so that the mobile terminal is more light and thin. Preferably 1.9mm < TTL <2.3mm.

In the present embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f4 of the fourth lens satisfy: 0.5< f 1/(f2+f4) <1.3. By limiting f 1/(f2+f4) to a reasonable range, the total length of the optical imaging system is reduced, the miniaturization of the module is realized, and the problem of increased tolerance sensitivity of the optical imaging system caused by excessive concentration of optical power is avoided. Preferably 0.75< f 1/(f2+f4) <1.25.

In the present embodiment, the effective focal length f5 of the fifth lens and the effective focal length f3 of the third lens satisfy: 0.2< f5/f3<2.9. By controlling f5/f3 within a reasonable range, a reasonable distribution of optical power is advantageous for improving imaging quality, while reducing the third lens optical power, the sensitivity to product manufacturing errors can be reduced. Preferably 0.4< f5/f3<2.8.

In the present embodiment, the curvature radius R1 of the surface of the first lens facing the object side and the curvature radius R2 of the surface of the first lens facing the image side satisfy: 2.4< R2/R1<3.5. By limiting R2/R1 within a reasonable range, the deflection angle of the marginal light rays in the first lens can be reasonably controlled, and the sensitivity of the optical imaging system can be effectively reduced. Preferably, 2.5< R2/R1<3.37.

In the present embodiment, the effective focal length f of the optical imaging system, the radius of curvature R4 of the surface of the second lens toward the object side, and the radius of curvature R8 of the surface of the fourth lens toward the image side satisfy: -1.3< f/(R4+R8) < -0.7. By controlling f/(r4+r8) within a reasonable range, by reasonably controlling this condition, it is possible to ensure that the optical imaging system has a large angle of view, and that the marginal rays have a reasonable angle of deflection at the fourth lens, reducing the sensitivity of the optical imaging system. Preferably, -1.2< f/(R4+R8) < -0.8.

In the present embodiment, the curvature radius R5 of the surface of the third lens facing the object side and the curvature radius R6 of the surface of the third lens facing the image side satisfy: 0.1< (R6+R5)/(R6-R5) <0.8. The deflection angle of the marginal light ray of the optical imaging system can be reasonably controlled by controlling the ratio of the sum of the curvature radius of the surface of the third lens facing the object side and the curvature radius of the surface of the third lens facing the image side to the difference between the curvature radius of the surface of the third lens facing the image side within a certain range, so that the sensitivity of the optical imaging system is effectively reduced. Preferably, 0.2< (R6+R5)/(R6-R5) <0.7.

In the present embodiment, the curvature radius R10 of the surface of the fifth lens facing the image side and the center thickness CT5 of the fifth lens satisfy: 1.4< R10/CT5<4.0. By controlling R10/CT5 within a reasonable range, the workability of the fifth lens can be ensured while reducing the sensitivity of the fifth lens. Preferably, 1.5< R10/CT5<3.6.

In the present embodiment, the sum Σct of the center thicknesses of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and the sum Σat of the air intervals between the adjacent lenses of the first lens to the fifth lens satisfy: 2.2< ΣCT/ΣAT <3.5. By limiting the sigma CT/sigma AT within a reasonable range, the length of the whole structure of the optical imaging system can be effectively controlled, the optical imaging system can have a compact structure, and the module miniaturization is facilitated. Preferably, 2.5< Σct/Σat <3.45.

In the present embodiment, the sum focal length f23 of the second lens and the third lens and the sum focal length f45 of the fourth lens and the fifth lens satisfy: 0< (f23+f45)/(f23-f45) <0.7. The contribution quantity of the aberrations of the two groups of lenses can be controlled by reasonably controlling the sum-difference ratio of the combined focal length of the second lens and the third lens to the combined focal length of the fourth lens and the fifth lens, and the contribution quantity is balanced with the aberrations generated by the front-end optical element, so that the aberrations of the optical imaging system are in a reasonable horizontal state. Preferably, 0.2< (f23+f45)/(f23-f 45) <0.6.

In the present embodiment, an on-axis distance SAG22 between an intersection point of the surface of the second lens facing the image side and the optical axis of the optical imaging system and an effective radius vertex of the surface of the second lens facing the image side, an on-axis distance SAG31 between an intersection point of the surface of the third lens facing the object side and the optical axis and an effective radius vertex of the surface of the third lens facing the object side, and an on-axis distance SAG42 between an intersection point of the surface of the fourth lens facing the image side and the optical axis and an effective radius vertex of the surface of the fourth lens facing the image side satisfy: 0.6< (SAG22+SAG31)/SAG 42<1.3. By controlling (SAG22+SAG31)/SAG 42 within a reasonable range, a better balance is facilitated to achieve the relationship of module miniaturization and relative illuminance of off-axis field of view. Preferably, 0.7< (SAG22+SAG31)/SAG 42<1.2.

In the present embodiment, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the edge thickness ET2 of the second lens, and the edge thickness ET3 of the third lens satisfy: 2.8< CT2/ET2+ET3/CT3<3.6. And the CT2/ET2+ET3/CT3 is controlled within a reasonable range, so that the processing manufacturability of the second lens and the third lens is improved, and the molding manufacturing difficulty is reduced. Preferably, 2.9< CT2/ET2+ET3/CT3<3.5.

In the present embodiment, the edge thickness ET5 of the fifth lens and the edge thickness ET4 of the fourth lens satisfy: 1.0< ET5/ET4<2.8. By limiting ET5/ET4 within a reasonable range, the edge structure of the optical imaging system can be effectively controlled, so that the optical imaging system has a compact structure, and the miniaturization of the optical imaging system is facilitated. Preferably 1.5< ET5/ET4<2.7.

Example two

As shown in fig. 1 to 18, the optical imaging system includes, in order from an object side to an image side thereof, a first lens having positive optical power, a second lens having a convex surface facing the object side, a third lens having a concave surface facing the image side, a fourth lens, and a fifth lens; the second lens has positive focal power, and the surface of the second lens facing the image side is a convex surface; the third lens has negative focal power, the surface of the third lens facing the object side is a concave surface, and the surface of the third lens facing the image side is a concave surface; the fourth lens has positive focal power, and the surface of the fourth lens facing the image side is a convex surface; the fifth lens has negative focal power, and the surface of the fifth lens facing the image side is a concave surface; wherein, the sum of center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens and the sum of air intervals SigaAT between adjacent lenses of the first lens and the fifth lens are satisfied: 2.2< ΣCT/ΣAT <3.5.

The positive and negative distribution of the focal power of each lens of the optical imaging system is reasonably controlled, so that the low-order aberration of the optical imaging system can be effectively balanced, the sensitivity of the tolerance of the optical imaging system can be reduced, the miniaturization of the optical imaging system is kept, and the imaging quality of the optical imaging system is ensured. The first lens and the second lens are provided with Cheng Zhengguang focal power, light rays can be effectively converged, the third lens and the fifth lens are negative focal power, the system can be ensured to maintain a larger image surface, the aberration of the optical imaging system can be effectively reduced by adopting the positive and negative focal power combination, the imaging quality is improved, meanwhile, the larger deflection of an optical path can be avoided, the positive and negative focal power is distributed in a staggered manner, the abnormal shape of a local lens caused by the excessive concentration of the focal power is avoided, and the processing is difficult. By limiting the sigma CT/sigma AT within a reasonable range, the length of the whole structure of the optical imaging system can be effectively controlled, the optical imaging system can have a compact structure, and the module miniaturization is facilitated.

Preferably, the sum Σct of the center thicknesses of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and the sum Σat of the air intervals between the adjacent lenses of the first lens to the fifth lens satisfy: 2.5< ΣCT/ΣAT <3.45.

In the present embodiment, the curvature radius R1 of the surface of the first lens facing the object side and the curvature radius R2 of the surface of the first lens facing the image side satisfy: 2.4< R2/R1<3.5. By limiting R2/R1 within a reasonable range, the deflection angle of the marginal light rays in the first lens can be reasonably controlled, and the sensitivity of the optical imaging system can be effectively reduced. Preferably, 2.5< R2/R1<3.37. In the present embodiment, the effective focal length f of the optical imaging system, the radius of curvature R4 of the surface of the second lens toward the object side, and the radius of curvature R8 of the surface of the fourth lens toward the image side satisfy: -1.3< f/(R4+R8) < -0.7. By controlling f/(r4+r8) within a reasonable range, by reasonably controlling this condition, it is possible to ensure that the optical imaging system has a large angle of view, and that the marginal rays have a reasonable angle of deflection at the fourth lens, reducing the sensitivity of the optical imaging system. Preferably, -1.2< f/(R4+R8) < -0.8.

Optionally, the optical imaging system may further include a filter for correcting color deviation and/or a protective glass for protecting the photosensitive element located on the imaging surface.

The optical imaging system in the present application may employ a plurality of lenses, such as the five lenses described above. By reasonably distributing the focal power, the surface shape, the center thickness of each lens, the axial distance between each lens and the like of each lens, the aperture of the optical imaging system can be effectively increased, the sensitivity of the lens is reduced, and the processability of the lens is improved, so that the optical imaging system is more beneficial to production and processing and can be suitable for portable electronic equipment such as smart phones and the like.

In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The aspherical lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality.

However, those skilled in the art will appreciate that the number of lenses making up an optical imaging system can be varied to achieve the various results and advantages described in this specification without departing from the scope of the application as claimed. For example, although the description has been made by taking five lenses as an example in the embodiment, the optical imaging system is not limited to include five lenses. The optical imaging system may also include other numbers of lenses, if desired.

Examples of specific surface types, parameters applicable to the optical imaging system of the above embodiment are further described below with reference to the drawings.

Any of the following examples one to six is applicable to all embodiments of the present application.

Example one

As shown in fig. 1 to 3, an optical imaging system according to an example one of the present application is described. Fig. 1 shows a schematic diagram of an optical imaging system configuration of example one.

As shown in fig. 1, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

The first lens E1 has positive power, a surface S1 of the first lens facing the object side is convex, and a surface S2 of the first lens facing the image side is concave. The second lens element E2 has positive refractive power, wherein a surface S3 of the second lens element facing the object side is concave, and a surface S4 of the second lens element facing the image side is convex. The third lens E3 has negative power, a surface S5 of the third lens facing the object side is concave, and a surface S6 of the third lens facing the image side is concave. The fourth lens element E4 has positive refractive power, wherein a surface S7 of the fourth lens element facing the object side is concave, and a surface S8 of the fourth lens element facing the image side is convex. The fifth lens E5 has negative power, a surface S9 of the fifth lens facing the object side is convex, and a surface S10 of the fifth lens facing the image side is concave. The filter E6 has a surface S11 of the filter facing the object side and a surface S12 of the filter facing the image side. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.36mm, the total length TTL of the optical imaging system is 2.02mm and the image height ImgH is 1.55mm.

Table 1 shows a basic structural parameter table of the optical imaging system of example one, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 1

In the first example, the surface of any one of the first lens element E1 to the fifth lens element E5 facing the object side and the surface facing the image side are both aspheric, and the surface shape of each aspheric lens can be defined by, but not limited to, the following aspheric formula:

Wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the aspherical i-th order. The following Table 2 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 that can be used for each of the aspherical mirrors S1-S10 in example one.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-3.6242E-01

4.2661E+00

-1.9409E+02

3.3669E+03

-3.5943E+04

2.0111E+05

-4.7592E+05

S2

-4.9543E-01

-4.6986E+00

-2.2237E+01

1.9473E+01

1.4497E+02

-1.3199E+04

7.5224E+04

S3

-1.0095E+00

-4.4503E+00

-2.5308E+02

5.5120E+03

-6.5388E+04

3.7118E+05

-7.4739E+05

S4

-7.1038E+00

7.8792E+01

-9.0216E+02

8.2480E+03

-5.4565E+04

2.1498E+05

-3.4818E+05

S5

-4.5535E+00

1.8546E+00

4.1032E+02

-4.2397E+03

1.8513E+04

-3.0720E+04

-1.7179E+03

S6

-1.1625E+00

-3.9799E+00

9.7881E+01

-6.9444E+02

2.5451E+03

-5.1904E+03

4.8301E+03

S7

5.6433E-01

4.0408E+00

-1.9930E+02

2.4259E+03

-1.6859E+04

7.1831E+04

-1.8462E+05

S8

5.3579E-01

1.1240E+01

-1.4979E+02

1.0259E+03

-4.4070E+03

1.1913E+04

-1.9365E+04

S9

7.7025E-01

-3.6100E+01

4.5281E+02

-3.7283E+03

2.1250E+04

-8.5682E+04

2.4792E+05

S10

-7.4089E+00

4.6004E+01

-2.5339E+02

1.0736E+03

-3.3874E+03

7.9193E+03

-1.3723E+04

Face number

A18

A20

A22

A24

A26

A28

A30

S1

0.0000E+00

S2

0.0000E+00

S3

0.0000E+00

S4

0.0000E+00

S5

0.0000E+00

S6

0.0000E+00

S7

2.6150E+05

-1.5593E+05

0.0000E+00

S8

1.7207E+04

-6.4229E+03

0.0000E+00

S9

-5.1856E+05

7.8361E+05

-8.4631E+05

6.3654E+05

-3.1659E+05

9.3571E+04

-1.2441E+04

S10

1.7591E+04

-1.6555E+04

1.1256E+04

-5.3673E+03

1.6994E+03

-3.2048E+02

2.7217E+01

TABLE 2

Fig. 2 shows an on-axis chromatic aberration curve of the optical imaging system of example one, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 3 shows a distortion curve of the optical imaging system of example one, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 2 and 3, the optical imaging system according to example one can achieve good imaging quality.

Example two

As shown in fig. 4 to 6, an optical imaging system of example two of the present application is described. In this example and the following examples, a description of portions similar to those of example one will be omitted for the sake of brevity. Fig. 4 shows a schematic diagram of the structure of an optical imaging system of example two.

As shown in fig. 4, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

In the present example, the total effective focal length f of the optical imaging system is 1.41mm, the total length TTL of the optical imaging system is 2.02mm and the image height ImgH is 1.55mm.

Table 3 shows a basic structural parameter table of the optical imaging system of example two, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 3 Table 3

Table 4 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example two, where each of the aspherical surface types can be defined by equation (1) given in example one above.

TABLE 4 Table 4

Fig. 5 shows an on-axis chromatic aberration curve of the optical imaging system of example two, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 6 shows a distortion curve of the optical imaging system of example two, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 5 and 6, the optical imaging system according to the second example can achieve good imaging quality.

Example three

As shown in fig. 7 to 9, an optical imaging system of example three of the present application is described. Fig. 7 shows a schematic diagram of the structure of an optical imaging system of example three.

As shown in fig. 7, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

The first lens E1 has positive power, a surface S1 of the first lens facing the object side is convex, and a surface S2 of the first lens facing the image side is concave. The second lens element E2 has positive refractive power, wherein a surface S3 of the second lens element facing the object side is concave, and a surface S4 of the second lens element facing the image side is convex. The third lens E3 has negative power, a surface S5 of the third lens facing the object side is concave, and a surface S6 of the third lens facing the image side is concave. The fourth lens element E4 has positive refractive power, wherein a surface S7 of the fourth lens element facing the object side is convex, and a surface S8 of the fourth lens element facing the image side is convex. The fifth lens E5 has negative power, a surface S9 of the fifth lens facing the object side is concave, and a surface S10 of the fifth lens facing the image side is concave. The filter E6 has a surface S11 of the filter facing the object side and a surface S12 of the filter facing the image side. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.36mm, the total length TTL of the optical imaging system is 2.00mm and the image height ImgH is 1.55mm.

Table 5 shows a basic structural parameter table of the optical imaging system of example three, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 5

Table 6 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example three, where each of the aspherical surface types can be defined by the formula (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-3.6658E-01

2.5326E+00

-7.9483E+01

1.2906E+02

9.1723E+03

-1.0619E+05

3.3509E+05

S2

-4.0077E-01

-1.1967E+01

2.4490E+02

-5.5405E+03

6.1994E+04

-3.6592E+05

8.8414E+05

S3

-9.8227E-01

-4.6531E+00

-1.7509E+02

3.6933E+03

-4.4543E+04

2.4433E+05

-4.3933E+05

S4

-5.1609E+00

-4.0137E+00

6.8878E+02

-8.4193E+03

4.4754E+04

-1.0461E+05

7.7867E+04

S5

-3.7414E+00

-3.8680E+01

1.0257E+03

-8.9016E+03

3.4853E+04

-4.6135E+04

-3.2510E+04

S6

-8.1944E-01

-1.4780E+01

2.2163E+02

-1.5146E+03

5.7459E+03

-1.1963E+04

1.0855E+04

S7

-6.2534E-01

8.8232E+00

-8.6870E+01

4.0504E+02

-7.4061E+02

-1.6461E+03

1.1414E+04

S8

-4.0031E-01

3.2391E+01

-3.2600E+02

1.8011E+03

-6.2432E+03

1.3802E+04

-1.8728E+04

S9

-1.0173E+01

1.7151E+02

-1.7146E+03

1.1150E+04

-5.0884E+04

1.7095E+05

-4.3684E+05

S10

-1.1325E+01

1.1798E+02

-8.6246E+02

4.2737E+03

-1.4801E+04

3.6733E+04

-6.6340E+04

Face number

A18

A20

A22

A24

A26

A28

A30

S1

0.0000E+00

S2

0.0000E+00

S3

0.0000E+00

S4

0.0000E+00

S5

0.0000E+00

S6

0.0000E+00

S7

-2.2756E+04

1.6548E+04

0.0000E+00

S8

1.4129E+04

-4.5263E+03

0.0000E+00

S9

8.6618E+05

-1.3375E+06

1.5816E+06

-1.3762E+06

8.2303E+05

-2.9955E+05

4.9660E+04

S10

8.7751E+04

-8.4794E+04

5.9076E+04

-2.8854E+04

9.3649E+03

-1.8125E+03

1.5820E+02

TABLE 6

Fig. 8 shows an on-axis chromatic aberration curve of the optical imaging system of example three, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 9 shows a distortion curve of the optical imaging system of example three, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 8 and 9, the optical imaging system according to example three can achieve good imaging quality.

Example four

As shown in fig. 10 to 12, an optical imaging system of example four of the present application is described. Fig. 10 shows a schematic diagram of the structure of an optical imaging system of example four.

As shown in fig. 10, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

In the present example, the total effective focal length f of the optical imaging system is 1.36mm, the total length TTL of the optical imaging system is 2.18mm and the image height ImgH is 1.55mm.

Table 7 shows a basic structural parameter table of the optical imaging system of example four, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 7

Table 8 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example four, where each of the aspherical surface types can be defined by the formula (1) given in example one above.

TABLE 8

Fig. 11 shows an on-axis chromatic aberration curve of the optical imaging system of example four, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 12 shows a distortion curve of the optical imaging system of example four, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 11 and 12, the optical imaging system as given in example four can achieve good imaging quality.

Example five

As shown in fig. 13 to 15, an optical imaging system of example five of the present application is described. Fig. 13 shows a schematic diagram of the structure of an optical imaging system of example five.

As shown in fig. 13, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

The first lens E1 has positive power, a surface S1 of the first lens facing the object side is convex, and a surface S2 of the first lens facing the image side is concave. The second lens element E2 has positive refractive power, wherein a surface S3 of the second lens element facing the object side is convex, and a surface S4 of the second lens element facing the image side is convex. The third lens E3 has negative power, a surface S5 of the third lens facing the object side is concave, and a surface S6 of the third lens facing the image side is concave. The fourth lens element E4 has positive refractive power, wherein a surface S7 of the fourth lens element facing the object side is concave, and a surface S8 of the fourth lens element facing the image side is convex. The fifth lens E5 has negative power, a surface S9 of the fifth lens facing the object side is convex, and a surface S10 of the fifth lens facing the image side is concave. The filter E6 has a surface S11 of the filter facing the object side and a surface S12 of the filter facing the image side. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.36mm, the total length TTL of the optical imaging system is 2.20mm and the image height ImgH is 1.55mm.

Table 9 shows a basic structural parameter table of the optical imaging system of example five, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 9

Table 10 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example five, where each of the aspherical surface types can be defined by equation (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-3.0748E-01

-2.6895E+00

3.8435E+01

-1.1835E+03

1.3980E+04

-8.7788E+04

2.0922E+05

S2

-7.4071E-01

-2.8281E+00

-1.2719E+02

1.8695E+03

-1.7810E+04

8.1231E+04

-1.2434E+05

S3

-1.2021E+00

-5.7645E-01

-4.7084E+02

9.2513E+03

-1.0292E+05

5.7788E+05

-1.1994E+06

S4

-8.0039E+00

9.8440E+01

-1.3772E+03

1.3546E+04

-8.1612E+04

2.7659E+05

-3.8903E+05

S5

-6.4859E+00

3.9631E+01

-2.6571E+02

3.0359E+03

-1.9878E+04

6.0365E+04

-6.7481E+04

S6

-1.2988E+00

-2.0291E+00

6.8459E+01

-4.7479E+02

1.7261E+03

-3.6661E+03

3.6535E+03

S7

8.8887E-01

-7.0831E+00

-1.1182E+01

5.0233E+02

-4.4268E+03

2.1124E+04

-5.8907E+04

S8

4.5650E-01

3.9205E+00

-4.5307E+01

2.7043E+02

-9.9148E+02

2.2089E+03

-2.8374E+03

S9

1.7446E+00

-2.2168E+01

1.3157E+02

-5.0062E+02

1.2485E+03

-1.9518E+03

1.5944E+03

S10

-3.8757E+00

1.4127E+01

-5.4430E+01

1.9066E+02

-5.3961E+02

1.1518E+03

-1.8032E+03

Face number

A18

A20

A22

A24

A26

A28

A30

S1

0.0000E+00

S2

0.0000E+00

S3

0.0000E+00

S4

0.0000E+00

S5

0.0000E+00

S6

0.0000E+00

S7

8.9823E+04

-5.7538E+04

0.0000E+00

S8

1.8983E+03

-5.0545E+02

0.0000E+00

S9

5.9814E+01

-1.4368E+03

1.1025E+03

7.9869E+01

-5.5449E+02

3.0237E+02

-5.4975E+01

S10

2.0486E+03

-1.6761E+03

9.7415E+02

-3.9154E+02

1.0332E+02

-1.6090E+01

1.1198E+00

Table 10

Fig. 14 shows an on-axis chromatic aberration curve of the optical imaging system of example five, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 15 shows a distortion curve of the optical imaging system of example five, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 14 and 15, the optical imaging system given in example five can achieve good imaging quality.

Example six

As shown in fig. 16 to 18, an optical imaging system of example six of the present application is described. Fig. 16 shows a schematic diagram of an optical imaging system configuration of example six.

As shown in fig. 16, the optical imaging system sequentially includes, from an object side to an image side: stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, filter E6, and imaging plane S13.

Table 11 shows a basic structural parameter table of the optical imaging system of example six, in which the unit of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 11

Table 12 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example six, where each of the aspherical surface types can be defined by equation (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-3.9686E-01

1.9187E+00

-1.2275E+02

2.1260E+03

-2.3805E+04

1.4044E+05

-3.5185E+05

S2

-9.2798E-01

-2.0137E+00

-1.9158E+02

3.4676E+03

-3.6047E+04

1.8823E+05

-3.8069E+05

S3

-1.2977E+00

-5.5273E+00

-2.6269E+02

4.5557E+03

-5.0617E+04

3.0665E+05

-6.7891E+05

S4

-8.1400E+00

1.0621E+02

-1.5834E+03

1.5875E+04

-9.1849E+04

2.8513E+05

-3.6208E+05

S5

-6.4424E+00

5.3168E+01

-6.8265E+02

8.3495E+03

-5.3269E+04

1.6193E+05

-1.8743E+05

S6

-1.0072E+00

-4.1114E+00

6.7552E+01

-3.6967E+02

1.1474E+03

-2.1731E+03

1.9632E+03

S7

2.7724E-01

6.5147E+00

-1.4118E+02

1.3231E+03

-7.7069E+03

2.8095E+04

-6.1708E+04

S8

1.4046E-01

1.1117E+01

-1.2446E+02

8.1533E+02

-3.3425E+03

8.3639E+03

-1.2264E+04

S9

2.4229E+00

-2.9031E+01

1.8419E+02

-8.1890E+02

2.6826E+03

-6.6090E+03

1.2283E+04

S10

-3.3506E+00

8.9053E+00

-2.2720E+01

5.9770E+01

-1.6078E+02

3.6826E+02

-6.3396E+02

Face number

A18

A20

A22

A24

A26

A28

A30

S1

0.0000E+00

S2

0.0000E+00

S3

0.0000E+00

S4

0.0000E+00

S5

0.0000E+00

S6

0.0000E+00

S7

7.4709E+04

-3.8446E+04

0.0000E+00

S8

9.6615E+03

-3.1618E+03

0.0000E+00

S9

-1.7082E+04

1.7531E+04

-1.3011E+04

6.7671E+03

-2.3346E+03

4.7942E+02

-4.4346E+01

S10

7.8665E+02

-6.9431E+02

4.3035E+02

-1.8270E+02

5.0518E+01

-8.1893E+00

5.9009E-01

Table 12

Fig. 17 shows an on-axis chromatic aberration curve of the optical imaging system of example six, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 18 shows a distortion curve of the optical imaging system of example six, which represents distortion magnitude values corresponding to different angles of view.

As can be seen from fig. 17 and 18, the optical imaging system given in example six can achieve good imaging quality.

In summary, examples one to six satisfy the relationships shown in table 13, respectively.

TABLE 13

Table 14 shows the effective focal lengths f of the optical imaging systems of examples one to six, and the effective focal lengths f1 to f5 of the respective lenses.

Example parameters	1	2	3	4	5	6
							f1(mm)	2.12	2.05	2.06	2.28	2.59	2.58
f2(mm)	1.29	1.37	1.43	1.31	1.27	1.11
							f3(mm)	-1.03	-1.09	-1.22	-0.87	-0.95	-0.90
f4(mm)	1.04	1.04	0.72	0.63	1.12	1.24
							f5(mm)	-1.23	-1.12	-0.65	-0.66	-2.16	-2.45
f(mm)	1.36	1.41	1.36	1.36	1.36	1.36
							TTL(mm)	2.02	2.02	2.00	2.18	2.20	2.20
ImgH(mm)	1.55	1.55	1.55	1.55	1.55	1.55

TABLE 14

The application also provides an imaging device, wherein the electronic photosensitive element can be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device may be a stand alone imaging device such as a digital camera or an imaging module integrated on a mobile electronic device such as a cell phone. The imaging device is equipped with the optical imaging system described above.

It will be apparent that the embodiments described above are merely some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical imaging system, characterized in that the optical imaging system has only five lenses, comprising, in order from an object side of the optical imaging system to an image side of the optical imaging system:

A first lens having positive optical power, a surface of the first lens facing the object side being a convex surface, and a surface of the first lens facing the image side being a concave surface;

a second lens having positive optical power, the surface of the second lens facing the image side being convex;

A third lens having negative optical power, a surface of the third lens facing the object side being a concave surface, and a surface of the third lens facing the image side being a concave surface;

a fourth lens having positive optical power, the surface of the fourth lens facing the image side being convex;

a fifth lens having negative optical power, a surface of the fifth lens facing the image side being a concave surface;

Wherein the on-axis distance from the object side surface of the first lens to the imaging surface of the optical imaging system

TTL, the maximum half field angle HFOV of the optical imaging system: 1.5mm <

TTL/tan(HFOV)<2.0mm；

The effective focal length f1 of the first lens, the effective focal length f2 of the second lens and the effective focal length f4 of the fourth lens satisfy the following conditions: 0.5< f 1/(f2+f4) <1.3;

The combined focal length f23 of the second lens and the third lens and the combined focal length f45 of the fourth lens and the fifth lens satisfy the following conditions: 0< (f23+f45)/(f23-f45) <0.7.

2. The optical imaging system of claim 1, wherein an on-axis distance TTL from a surface of the first lens facing the object side to the imaging surface satisfies: 1.8mm < TTL <2.4mm.

3. The optical imaging system of claim 1, wherein an effective focal length f5 of the fifth lens and an effective focal length f3 of the third lens satisfy: 0.2< f5/f3<2.9.

4. The optical imaging system according to claim 1, wherein a radius of curvature R1 of a surface of the first lens facing the object side and a radius of curvature R2 of a surface of the first lens facing the image side satisfy: 2.4< R2/R1<3.5.

5. The optical imaging system according to claim 1, wherein an effective focal length f of the optical imaging system, a radius of curvature R4 of a surface of the second lens facing the object side, and a radius of curvature R8 of a surface of the fourth lens facing the image side satisfy: -1.3< f/(R4+R8) < -0.7.

6. The optical imaging system according to claim 1, wherein a radius of curvature R5 of a surface of the third lens facing the object side and a radius of curvature R6 of a surface of the third lens facing the image side satisfy: 0.1< (R6+R5)/(R6-R5) <0.8.

7. The optical imaging system according to claim 1, wherein a radius of curvature R10 of a surface of the fifth lens facing the image side and a center thickness CT5 of the fifth lens satisfy: 1.4< R10/CT5<4.0.

8. The optical imaging system according to claim 1, wherein a sum Σct of center thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and a sum Σat of air intervals between adjacent lenses of the first lens to the fifth lens satisfy: 2.2< ΣCT/ΣAT <3.5.

9. The optical imaging system according to claim 1, wherein an on-axis distance SAG22 between an intersection point of the surface of the second lens facing the image side and an optical axis of the optical imaging system to an effective radius vertex of the surface of the second lens facing the image side, an on-axis distance SAG31 between an intersection point of the surface of the third lens facing the object side and the optical axis to an effective radius vertex of the surface of the third lens facing the object side, and an on-axis distance SAG42 between an intersection point of the surface of the fourth lens facing the image side and the optical axis to an effective radius vertex of the surface of the fourth lens facing the image side satisfy: 0.6< (SAG22+SAG31)/SAG 42<1.3.

10. The optical imaging system according to claim 1, wherein a center thickness CT2 of the second lens on the optical axis, a center thickness CT3 of the third lens on the optical axis, an edge thickness ET2 of the second lens, and an edge thickness ET3 of the third lens satisfy: 2.8< CT2/ET2+ET3/CT3<3.6.

11. The optical imaging system of claim 1, wherein an edge thickness ET5 of the fifth lens and an edge thickness ET4 of the fourth lens satisfy: 1.0< ET5/ET4<2.8.